J.O. Dzięgielewski

THE SYNTHESIS, CRYSTAL, MOLECULAR AND ELECTRONIC STRUCTURES OF TRIBROMO(NITROSYL) BIS(TRIPHENYLPHOSPHINE OXIDE) RHENIUM(II) AND TRIBROMO(NITROSYL) BIS(TRIPHENYLPHOSPHINE)RHENIUM(I)

Abstract Gaseous nitric oxide reacts with a benzene solution of [ReOBr3(PPh3)2] to give [ReBr3(NO) (OPPh3)2] (1). When the reaction is carried out in the presence of an excess of free triphenyl-phosphine, the product is [ReBr3(NO)(PPh3)2] (2). The latter is also isolated in the reaction of 1 with PPh3. This paper, apart from the synthetic methods, presents spectroscopic and magneto-chemical measurements, and crystal, molecular and electronic structures for 1 and 2.

The crystal and electronic structure of the complex [ReCl4(PPh3)2]

Abstract The crystallographic structure of the complex trans-[ReCl4(PPh3)2] was determined and the spectroscopic characterization of the complex was established. Its electronic structure was also investigated (10Dq = 17,889 cm−1, Ds = −4091 cm−1, Dτ = 136 cm−1, B = 473 cm−1, C = 2175 cm−1)

Reactivity of [ReOX3(AsPh3)2] (X = Cl, Br) complexes towards gaseous nitric oxide. Crystal, molecular and electronic structure of [ReBr3(NO)(OAsPh3)2], [ReCl3(NO)(AsPh3)2][ReCl4(AsPh3)2], [ReCl4(OASPh3)2] and [ReBr3(NO)(AsPh3)2]

Abstract The reactions of the complexes [ReOX 3 (AsPh 3 ) 2 ] (X=Cl, Br) with gaseous nitric oxide and the reactions of the compounds [NBu 4 ] 2 [ReX 5 (NO)] (X=Cl, Br) with an excess of triphenylarsine have been examined. [ReOBr 3 (AsPh 3 ) 2 ] reacts with nitric oxide to give mer , cis -[ReBr 3 (NO)(OAsPh 3 ) 2 ] ( 1 ), whereas the reaction of the chlorine oxocomplex with NO leads to three products: [ReCl 3 (NO)(OAsPh 3 ) 2 ] ( 2 ), mer , trans -[ReCl 3 (NO)(AsPh 3 ) 2 ][ReCl 4 (AsPh 3 ) 2 ] ( 3 ) and cis -[ReCl 4 (OAsPh 3 ) 2 ] ( 4 ). The compounds [NBu 4 ] 2 [ReX 5 (NO)] (X=Cl, Br) react with an excess of AsPh 3 to give 3 and mer , trans -[ReBr 3 (NO)(AsPh 3 ) 2 ] ( 5 ), respectively. The complexes obtained in these reactions have been characterised by IR, UV–Vis and magnetical measurements. Crystal and molecular structures have been determined for complexes 1 and 3 – 5 . EPR spectra have been recorded for compounds 1 and 5 .

Synthesis, spectroscopic investigation and X-ray structure of mononuclear and binuclear oxo complexes of rhenium(V) with pyrazolato ligands

The [{Re(O)Cl(PPh3)}2(μ-O)(μ-N2C3H3)2] (1), [{Re(O)Br(PPh3)}2(μ-O)(μ-N2C3H3)2] (2), [ReOCl2{η2-N2C3H3CMe2O}(PPh3)] (3) and [ReOBr2{η2-N2C3H3CMe2O}(PPh3)] (4) complexes have been synthesized by reacting [ReOX3(PPh3)2] with an excess of pyrazole under different conditions. The rhenium(V) centers of (1) and (2) are linked through two bridging pyrazolato anions and an oxo group. The rhenium(V) atoms in mononuclear complexes (3) and (4) are six coordinated in an octahedral environment with a trans arrangement of the oxo group and oxygen atom of anionic bidentate ligand C3H3N2C(Me)2O− formed in the reaction of pyrazole and Me2CO.

The synthesis, spectroscopic characterisation, crystal and molecular structure of two novel bent oxo-bridged dimers of rhenium(V) with μ-benzotriazolate ligands

Abstract Refluxing of [ReOX3(PPh3)2] (X=Cl, Br) complexes with 4 equiv. of benzotriazole in a mixture of ethanol+acetone affords symmetrically substituted dinuclear rhenium [{Re(O)X(PPh3)}2(μ-O)(μ-C6H4N3)2] complexes (1 and 2, respectively). Benzotriazole is capable of coordinating in the neutral and anionic mode to give mono- and polynuclear transition metal complexes. The neutral benzotriazole can be coordinated in a monodentate fashion through N(3) and in a bridging way through N(2)–N(3) atoms, whereas the benzotriazolate anion is coordinated in N(1) monodentate, N(1)–N(2) and N(1)–N(3) bridging bidentate or N(1)–N(2)–N(3) bridging tridentate bonding modes. The rhenium(V) centers of 1 and 2 are linked through two N(1)–N(2) bridging benzotriazolato anions and an oxo group. Due to the geometric constraints of the two bridging N-donor ligands the {Re2O3} unit in 1 and 2 is bent.

Preparation and spectroscopic characterization of [Re(NO)2X2LL2] (X = Cl, Br, I; L2 = 2PPh3, dppe). application of [Re(NO)2BBr2LL2] in oxidation of olefins

Abstract A simplified method of synthesis of dinitrosyl complexes [Re(NO)2XX2LL2], where X = Cl, Br, I and L2 = 2PPh3 or dppe, is described and spectroscopic characterization of the complexes is presented. The application of [Re(NO)2BBr2LL2] for the oxidation of cyclohexene is also discussed.

Synthesis, spectroscopic characterization, crystal and molecular structure of fac-[ReO3Br(phen)]

A new rhenium oxo-complex fac-[ReO3Br(phen)] has been obtained in high yield from the direct reaction of ammonium perrhenate with 1,10-phenanthroline in hydrobromic acid and characterized by X-ray diffraction and IR and UV-Vis spectra.

The Synthesis, Crystal, Molecular and Electronic Structure of [ReCl2(NO)(py)3]

In line with our investigations of rhenium nitrosyl complexes, we have studied the reaction of [ReCl3(NO)(OPPh3)(PPh3)] with pyridine. The [ReCl2(NO)(py)3] complex obtained in this reaction has been characterised by IR, electronic spectra and magnetochemical measurements; ligand field parameters and the electronic structure have been determined. The crystal and molecular structure of [ReCl2(NO)(py)3] has been solved by the heavy atom method. Crystals of [ReCl2(NO)(py)3] contain distorted octahedral molecules with the pyridine ligands in the mer-arrangement. The nitrosyl group is coordinated linearly to the rhenium atom as NO+.

Reactivity of ATP with ReOCl3(PPh3)2

The nuclidic properties of technetium-99m make this isotope an ideal radionuclide for the development of scanning agents in diagnostic medicine [1]. In fact, technetium-99m-labeled complexes have been a major contributing factor to the rapid growth of nuclear medicine [2].